MATLAB: How do i combine several matrix in one

for loopprocess a sequence of files

Hi,
I have 5 tests (martix (1000×4)), i would like to use a loop to obtain all possible sets of 2 tests and combine each of them (for example 1.txt;2.txt in one matrix)
for example
1.txt
2.txt
3.txt
4.txt
5.txt
Thanks a lot